Existing Respirator Materials Prove Effective For Certain Nanoparticles

At this morning's session of the International Conference on Nanotechnology Occupational & Environmental Health & Safety in Cincinnati, Ohio, Daniel Japuntich, Division Scientist at 3M, presented "Filtration and Respirators: Current Knowledge."  Japuntich shared 3M's research findings indicating HEPA respirator materials are effective in filtering nanoparticles down to three (3) nanometers in size. 

The 3M research found nanoparticles act as solids, "obey the laws of physics," and fit nicely within existing filtration models.  Thus, Japuntich concluded existing NIOSH respirator standards under 42 CFR 84 should be sufficient for many nanorelated uses.  Japuntich noted the efficacy of filter materials must be evaluated in the context of a complete workplace respirator program including hazard measurement and assessment, face-piece choice, face fit testing, and worker training programs.

Another conference presentation by Michele Ostraat, a Research Engineer at DuPont, discussed similar findings by the Nanoparticle Occupational Safety and Health Consortium. Ostraat spoke regarding the Consortium's recent aerosol chamber research studies on a variety of respirator material using six different types of nanoparticles.  Ostraat posed that, while existing respirator material proved effective for nanomaterials, filter efficacy for nano-aerosols decreases as exposure time increases in certain instances.  The Consortium intends to publish several papers in 2007 setting forth its research findings in detail.  Ostraat also explained the Consortium's parallel goals of making consistent nano-aerosols for research purposes (which it has already accomplished), and creating a reliable, inexpensive, portable, nanoparticle measuring device (which it hopes to unveil by mid-2007). 

NIOSH to Test Certified Respirators

The National Institute of Occupational Health and Saftety's (NIOSH)National Personal Protective Technology Laboratory (NPPTL) at NIOSH recently announced it intent to test currently certified repirators to determine whether they protect wearers against nanoparticle inhalation.  The NIOSH testing follows up on a University of Minnesota study pointing to the effecacy electrostatically charged filters in screening out nano-sized particles.  NPPTL also intends to conduct tests to determine whether nanoparticles will penetrate approved personal protective clothing.  Along with its announcement, NPPTL also noted that there are currently no specific exposure limits for nanoparticles, and that the decision to wear repirators is left to professional judgment. 

Inside OSHA, November 13, 2006, Vol. 13 No.23.